Transceiving circuit arrangement



April 11, 1950 A. VAN WEEL 2,503,782

TRANSCEIVING CIRCUIT ARRANGEMENT Filed Feb. 12, 1947 1:5 *IFY 6 a" 3 1::

r/ w/mr/m/vs (f/V67? CE/I/[R R A VA N WEEL INVEN'TOR E E v BY AGENT Patented Apr. 11, 1950 UNITED PATENT OF F LICE I 2,503,782 v rR'AnsoEIvING CIRCUIT ARRANGEMENT Adelb'ert van We'el, Eindh'oven, Netherlands, us-

"signer to Hartford National Bank and Slirust Company, Hartford, Conn., as trustee "Application February 12, 1947,, "Serial 'No. "728343 In .theNetherlands July "28, 1944 Section 1, Pub1icmawz69o, August 8,1946 -Bat'ent expires July-28,1964

'7 Claims. (01. 250-9) incoming oscillations are ted in push-pull' and the local oscillations. are supplied in single phase, means being provided which permit the said mixing systems'orapairof push-pull connected highfrequency amplification systems precedin g them 'to be coupled'ba'ck in such amanner that these systems generate oscillations-that may be trans- "mittedby meansnf adipoleantenna.

In a particular iorm oi construction of this "circuit not only the push-pun circuit, through which the incoming oscillations are supplied to theimixing systems, is t-uned 'to the-frequency of the incoming oscillations, but 'also the single phase circuit, through which the-local oscilla- -ti'ons are fed to "the mixing systems, is tuned to the frequency ofthe local'osclllations to be used for reception. Means arefprovioled, moreover, to "couple the mixing systems back in such a, manner as to generate the local oscillations in the "said sin'gle-p'hase circuit. The single-phase circuit consists of the parallel-connected impedances "of 'both halves of the push pull circui'tythe parallelconnected'inputimpedances o'ithe'two'mixing-systems and the'impedances'wliichthe input circuits of the two systems have .in common.

In the present case thefexpression pushepull circuit is tobe understoodto mean the assembly of impe'dan'ces available i-between two not directly interconnected input electrodes 'o'fthe mixing systerns, in which circulate currents having the frequency of the incoming oscillations. The expression input circuitof a mixing system is to be understood'to mean all impedances available between the input electroiiles 'ofthe mixing system, in which circulate currents associated with this system and having "the .fre'quen'cy of the local (Oscillations.

this proves to'he .dependent upon a yery accurate adjustment-of the circuit, whichiis verydifificult realize. Therefore, according to the invention,

means areapnovided vby which the circuit .can

automatically: exchanged overzalternately 7 -55 one kind of oscillation "to the other according transmissionito recention and conversely.

One formioftconstruction :o'f-the circuit accord- .ing to the invention comprises means which provide that, in the absence of :a modulation signal to be transmitted, exclusively the single-phase oscillations are produced. On the appearance of .a modulation signal exclusively, the push-pull oscillations are generated automatically, for -instance by dampi-ng'the single-phase circuit.

In another formmiconstruction of the circuit .:according to the .rirrvention, means are :provided which permit :the :circuit continuously to be changed over alternately ifrom transmission to reception and conversely-ate frequenc outsid'e the.

range of frequencies of :the incoming or transmitted low frequency oscillations =(alternating afre- :quency).

In the first-.nrentioned form of construction-of the invention, the circuit is :normally adjusted for reception. At thi time only single-phase oscillations :are produced, these being used as local oscillations .As .soon, however, as transmission is "desired, which moms, for instance, in a telephony transmitter Whenw'ords are :spoken :into the mi- :cronhone, the single-phase circuit is damped. Damping "may, itor instance, be effectua'ted by means ofa diode. lit this time push-fpulloscilla- Iti'o'n (instead of the "single-phase oscillation are generated, so that the circuit is changed-over "to transmission. 'When the modulation-signal ceases, the damping of the single-phase circuit is automatically cut out and the circuit generates local oscillations, so "that the circuit operat'es again as a receiver.

"In the last-mentioned form'of construction the circuit is continually .changed-over-'preferably at n super-sonic frequency-from transmission to reception and conversely, whichp'ermits conversati-on from both sides "in a'nor'm'al way.

In this form of construction, as "well as 'in the first-ment'ioned 'con's'truction, the circuit is pref-- -erably adjusted in such manner "as to generate under all circum's'tance's one of the two oscillations "(single-phase oscillation, push-pull oscillation) and "so as to generate, exclusively by damping one circuit, thekind of oscillations pertaining to "the other circuit.

oscillation astsoon Sas the single-phase circuit damped, or'the circuittmay be adjusted in such a manner tha'tit 'nas s'es' over automatically from lar transmission system in such a manner that when the signal transmitted by one circuit arrives at the other circuit, the last-mentioned circuit receives and conversely.

The automatic changing-over from transmission to receptionand conversely may also be used in circuits in which the functions of the pushpull circuit and the single-phase circuit are changed.

In order that the invention may be clearly understood and readily carried into effect, it will now be set out more fully with reference to the accompanying drawings representing, by way of example, one embodiment thereof.

Figure 1 shows a schematic diagram of one embodiment of the invention; and V Fig. 2 shows a block diagram of a further embodiment of the invention- Fig. 1 represents a transceiving circuit in which the dipole antenna I, I" is used both for re-, ceiving and for transmitting oscillations. When it is used as a receiving antenna the incoming oscillations are fed through a Lecher line 2', 2" to the input electrodes of two push-pull connected triodes 3', 3". The Lecher line 2, 2" is tuned, through the intermediary of a short circuit bridge 4, to the frequency of the incoming oscillations. The short-circuit bridge 4 is connected to earth through a variable impedance 5, and through a resistance 6 to a source of potential (not represented) which supplies a suitable negative bias for the control grids of the triodes 3, 3".

A resonant circuit tuned to the intermediate frequency and consisting of two inductances 1, 1" and two condensers 8, 8" is connected in push-pull to the anodes of the two triodes. In series with coils I, 1" are connected high-frequency choke coils 9, 9 which serve to prevent a transfer of the high-frequency oscillations to the receiver parts next to the mixing stage. The junction of coils l, 7 is connected to earth through a condenser 10, which practically constitutes a short-circuit with regard to the inter- ,mediate oscillations, and through a terminal I I to the positive terminal of a source of anode potential (not represented). Furthermore, coils 1', 1" are inductively coupled with a second intermediate frequency circuit which consists of a coil I2 anda condenser l3 from which the output voltage of the circuit is taken. 1

inputcircuit, which consists of the series-connec- *ti'on of the impedance 5; the'variable impedance =niitted by the dipole antenna 16 connected between the junction of the oathodes and earth, the parallel-connected impedances of both halves of the push-pull circuit and the parallel-connected input impedances of the two triodes, is tuned to the frequency of the local oscillations, for instance, by adjustment of the variable impedances 5 and I8. Moreover, by a suitable adjustment of the impedances 5 and I6, antenna I, I" may be connected at a voltage node of the local oscillations, thus preventing the antenna from radiating these oscillations.

The inductance coils l4, 14 inserted in the anode circuits of the triodes 3', 3", together with the anode control-grid capacities of the triode systems, bring about such a feedback that these systems generate oscillations which vary symmetrically with respect to earth and are transl, I". These oscillations may, for instance, be modulated by supplying a variable anode voltage to the terminal I I.

The inductances l4, 14" bring about a negative damping of the push-pull circuit, which leads to the production of the oscillations to be transmitted, and in addition a negative damping of the single-phase input circuit which is tuned to the frequency of the local oscillations. It is therefore possible for the circuit itself to produce the local oscillations. The tendency to generate in the same phase i. e. to produce the local oscillations, is further enhanced by the presence of the inductance coil l5. If this tendency is to be subdued the inductance coil l5 may be replaced by a condenser.

The circuit-arrangement is now adjusted in such manner that, normally, only single-phase local oscillations are produced; consequently the circuit acts normally as a receiver. Furthermore, the adjustment of the circuit is such that upon damping of the single-phase circuit the circuit arrangement immediately produces the push-pull oscillation. According to the invention this damping is automatically brought about as soon as a signal is to be transmitted. One and the other is realized by the circuit part on the lefthand side of the short-circuit bridge 4.

The signal to be transmitted is supplied to the terminals bearing the reference numeral I! in the drawing and is fed, through a condenser Hi, to the control grid of a triode l9. Between the control-grid and the cathode of this triode is connected a leakage resistance 20. The cathode lead of the'triode l9 includes a resistance 2| which forms at the same time part of a circuit comprising a diode 22, a choke 23 and a resistance 24. The diode 22 receives, through a resistance 25 and the aforesaid choke 23, a positive voltage from a source of potential (not represented). The anode of the diode is connected to the shortcircuit bridge 4 through a blocking condenser 26.

In the absence of a modulating signal, the cathode lead of the triode I9 is traversed by a comparatively strong current which causes, through the resistance 2i, such a voltage loss that the diode 22 is not capable of carrying current, so that it cannot havea damping efi'ect on the single-phase" circuit. In this case, consequently, solely the local oscillations are generated and the circuit acts as, a receiver.

As soon, however, as a modulation signal appears at the terminals I1, the control-grid of the triode becomes more negative, due to the rectification occurring; the current in the cathode lead of the triode I 9 decreases, the voltageloss through the resistancell falls ofi and the diode among-182 2z'becomes'iconductiva' GWing'tO'ithis thesingIee 'tial: state is resumed" and the circuitfunctions again as a receiver.

The aforesaid circuit may also be usedinan arrangement which is continuously: changed over alternately from transmission to reception: and

conversely at a frequency outside the range" of frequencies of the incoming or transmitted low frequency oscillations. When supplying, in efiect, avoltage having the alternating frequency instead of the modulating'signal to the terminals 1 l1, thecircuit is continuously changed over from reception to transmission and'conversely in the 'rhythm'of this'frequency, in the aforesaid man-- her.

this' case', with both ofthe' transceiving circuits of the transmission system', the emitted energy with as pleasant an effect as possible, we preferably proceed as follows.

In" Fig. 2', the transceiving circuitsare shown, one represented by A. In A, the alternating frequency is produced and used, whereas in the other circuit B avoltage having the alternating frequenoy'is picked up, amplified and utilized. The periodical changing-over from transmission to receptionand conversely in the circuit I3 may be displaced inphase with respect to' the alternating frequency picked up, in such a manner that the reception ofthetransmitter A is a maxi-' mum at B.

After this the value of' the alternating frequency'iscontrolled at A in such a manner that the transmitter B-is received with a maximum intensityat A". With this adjustment the alternating frequency, with which the circuit" 13 is operated is, of course, also varied automatically.

Such a controlis necessary in conjunction with the transit time of the electromagnetic waves between the two pointsA and B. If the alternating frequency is correctly adjusted, in accordance with what has been said above, this transit time substantially corresponds'with half the-period of oscillation or with an odd multiple of half the period of oscillation of the alternating frequency. In this case the energy issued by the transmitter Ais completely captured by B, and conversely the energy issuedby'B is completely captured by A.

What I claim is: t

l. Transceiver apparatus adapted selectively to generate high frequency oscillation and to mix incoming signals with assource of local oscillations comprising, first and second thermionic discharge systems having each a cathode, input electrode and output electrode, means to transfer the incoming signals .to the input electrodecathode circuit of the said first and second thermionic discharge systems in push-pull, single phase means to couple the source of local oscillations to the input-electrode-cathode circuit of the said first and second thermionic discharge systems, an output stage, means to couple the said output stage to the output electrodecathode circuit of the said first and second thermionic discharge systems, back coupling means applied to the output electrode-cathode circuit of: thez said: first and second. thermionic discharge: systems whereby said thermionic. dis charge systems:- are 1 caused: tc--- oscillate,- a source of control signals, and means'to. damp the source of local oscillations-in accordance with the said control" signals, said latter means comprising a unidirectional: conductor in, parallel with. the source of local oscillations "and means to render thesaid unidirectional conductor conductivein accordance with thesaid controlsignals.

2. In a" transceiver, a circuit arrangement adapted selectively to generate highfrequency oscillation of a given frequency and to mix in coming signals withasource of local oscillations comprising, first'and second thermionic discharge tubes having eacha'v cathode, grid and anode, push-pull means to transfer the incoming sig nals to the grid-cathode circuit of" the said first and second thermionic discharge tubes, single phase means to-couplethe source ofrlocal oscillations to the grid-cathode circuit: of the said first and second thermionic discharge" tubes, an outputstage; means to couple the said output stage to the anode-cathode circuit of the-said first and second thermionictdischarge tubes, back coupling means applied to the anode-cathode circuit of" the said first and. second thermionic discharge tubes whereby said thermionic discharge tubes Y, are caused to oscillate'upon damping of the said source of local oscillations, a source of modulating signals, and" means to damp the source of a local oscillationsin accordance. withthe said modulating signals, said latter'means'comprising a diode connected in parallel with the source of" local oscillations and means to render thesaid diode conductive in accordance-with the said modulating signal;

3. In a transceiver, a circuit arrangement adapted selectively to generate high frequency oscillation of a 'givenfre'quency and to mixincoming signals of ,a" given frequency with a source of' local oscillations comprising, first and secondthermionic discharge tubes having each a cathode, grid-and anode, push-pull means to transfer the incoming signals to the grid-cathode circuit of the said first andsecond thermionic discharge tubes, single phase means to couple the'source of "local oscillations to the'grid-cathode=circuit of the said first and second thermionic discharge tubes, an output stage, means to couple the said output stage to the anode-cathode cir cuit'of the said firstand second thermionic discharge tubes, back coupling means applied to the anode cathode circuit of the said first and second thermionic discharge tubes whereby said thermionic discharge tubes are caused to oscillate upon damping of'the said sourceof local oscillations, a source of modulating intelligence having a given range of frequencies, means to apply-said source of'modulating intelligence to the said first and second thermionic discharge tubes, asource of control signals having a frequency other than that of the generated high frequency oscillation, of the incoming signals and the said source of modulating intelligence and means to damp the source of local oscillations in accordance with the said control signals, said latter means comprising a diode connected in parallel with the source of local oscillations and means to render the said diode conductive in accordance with the said control signals.

4. In a, transceiver, a, circuit arrangement adapted selectively to generate high frequency oscillation of, a given frequency and to mix incoming signals having a different frequency with a source of local oscillations comprising, first and second thermionic" discharge tubes having each a cathode, grid and anode, means to transfer the incoming signals to the grid-cathode circuit of the said first and second thermionic discharge tubes in push-pull, single phase means to couple the source of local oscillations to the grid-cathode circuit of the said first and second thermionic discharge tubes, an output stage, means to couple the said output stage to the anode-cathode circult of the said first and second thermionic discharge tubes, back coupling means applied t the anode-cathode circuit of the said first and second thermionic discharge tubes whereby said thermionic discharge tubes are caused to oscillate upon damping of the said source of local oscillations, a source of modulating signals, and means to damp the source of local oscillations in accordance with the said modulating signals, said latter means comprising a unidirectional conductor in parallel with the source of local oscillations, and means to render the said unidirectional conductor conductive in accordance with the said modulating signal.

5.'In a transceiver, a circuit arrangement adapted selectively to generate high frequency oscillation of a given frequency and to mix incoming signals having a difierent frequency with a source of local oscillations comprising, first and second thermionic discharge tubes having each a cathode, grid and anode, means to transfer the incoming signals to the grid-cathode circuit of the said first and second thermionic discharge tubes in push-pull, single phase means to couple the source of local oscillations to the grid-cathode circuit of the said first and second thermionic discharge tubes, an output stage, means to couple the said output stage to the anode-cathode circuit of the said first and second thermionic dis charge tubes, back coupling means applied to the anode-cathode circuit of the said first and second thermionic discharge tubes whereby said thermionic discharge tubes are caused to oscillate upon damping of the said source of local oscillations, a source of modulating intelligence having a given range of frequencies, means to apply said source of modulating intelligence to the said first and second thermionic discharge tubes, a source of control signals having a frequency other than that of th generated high frequency oscillation, of the incoming signals and the said source of modulating intelligence and means to damp the source of local oscillations in accordance with the said control signals, said latter means comprising a diode connected in parallel with the source of local oscillations and means to render the said diode conductive in accordance with the said control signals.

6. Transceiver apparatus adapted selectively to generate high frequency oscillation and to mix incoming signals with a source of local oscillations comprising, first and second thermionic discharge tubes having each a cathode, grid and anode, means to transfer the incoming signals to the input electrode-cathode circuit of the said first and second thermionic discharge tubes in push-pull, single phase means to couple the source of local oscillations to the grid-cathode circuit of the said first and second thermionic discharge tubes, an output stage, means to couple the said output stage to the anode-cathode circuit of the said first and second thermionic discharge tubes, back coupling means applied to the anodecathode circuit of the said first and second thermionic discharge tubes whereby said thermionic discharge tubes are caused to oscillate upon damping of the said source of local oscillations, a source of control signals of a given frequency, means to damp the source of local oscillations in accordance with the said control signals of a given frequency, said latter means comprising a diode in parallel with the source of local oscillations and means to render the said diode conductive in accordance with the said control signals, and a second transceiver apparatus having means to switch from transmission to reception being equal to the said control frequency.

'l. Transceiver apparatus adapted selectively to generate high frequency oscillation and to mix incoming signals with a source of local oscillations comprising, first and second thermionic dis charge tubes having each a cathode, grid and anode, means to transfer the incoming signals to the input electrode-cathode circuit of the said first and second thermionic discharge tubes in push-pull, single phase means to couple the source of local oscillations to the grid-cathode circuit of the said first and second thermionic discharge tubes, an output stage, means to couple th said output stage to the anode-cathode circuit of the said first and second thermionic discharge tubes, back coupling means applied to the anode-cathode circuit of the said first and second thermionic discharge tubes whereby said thermionic discharge tubes are caused to oscillate upon damping of the said source of local oscillations, a source of control signals of a given frequency, means to damp the source of local oscillations in accordance with the said control signals of a given frequency, said latter means comprising a diode in parallel with the source of local oscillations and means to render the said diode conductive in accordance with the said control signals, and a second transceiver apparatus located at a given distance and having means to switch from transmission to reception selectively at a given frequency, said frequency being equal to the said control frequency and being an odd submult-iple of twice the period of the transit time to the said second transceiver.

ADELBERT VAN WEEL.

No references cited. 

